The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1887-10-08
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.
ASTRONOMICAL oBsERvAToRIEs.

ASTRONOMICAL oBsERvAT0RIEs.
Very ancient observatories are said to have been
erected on the top of the Osymandyas, in Egypt;
and at Benares. The first in authentic history
was erected by Ptolemy Softer at Alexandria,
about 800 B. G.. Of prominent modern observa-
tories the dates are French Royal, 1867 Green
wich, 1875 Nuremburg, 1878; Pekin, about 1850;
Oxford, 1893; Edinburgh, 1776; Dublin, 1888
Armagh, 1898; Cambridge, England, 1924;
Williams College, first in the United States, 1886
Pulkowa, 1899 Cambridge, Mass, 1910 Wash
ington, 1912 Liverpool, 1874; AnnArbor,s 1854;
Albany 1856. The Lick Observatory in California,
equipped with the largest refractor yet made, was
endowed with 500, 900 in 1874.
CHEMICAL MILESTONE.
The discovery of new gas is a rare and import
ant event to chemists Such discovery has been
announced in Germany by DIR. Theodor Curtius,
who has succeeded in preparing the long sought
hydride of nitrogen, amidogen, diamide, or hyda-
zine, as it is variously called. This remarkable
body, which has hitherto baffled all attempts at
isolation, is now shown to be a gas, perfectly
stable up to very high temperature, of peculiar
odor differing from that OF ammonia, exceedingly
soluble in water, and of basic properties. In COM
position it is nearly identical with ammonia, both
being compounds of nitrogen and hydrogen.
THE ATLANTIC WINTER.
series of sem-diurnal weather charts for the
North Atlantic from Nov Sth 1882, to Feb. I4th,
1883, has been issued by the Meteorological
Council of Great Britain, and supplements SINH
lar series which has been prepared to show the
weather of the summer and autumn months.
Striking difference in the two series is given by
the more disturbed character of the winter, and
the great range of air-pressure at that season.
The high barometer reading of 80 to 30.3
inches, which extends most of the North
Atlantic in summer, is attended to the northward
by low area of 29.2 to 29.5, the depression usu-
oII ho,, g. I:.La
storms in British latitudes. In winter the barOm-
eter often rises as high as 3O7 in mid-ocean and
above 81 in North America, and falls to 20 and
sometimes below %, frequent and severe storms
being produced. The progress of disturbances in
many instances can be traced for days together on
the charts,-the severe storm of Nov. 19 in the
British Islands, for instance, seeming to have
formed over central North America on Nov. O.
The winter gales often of great extent, that of
JAM % having been present at the same time in
Hudson's Bay, Labrador, Newfoundland and
Norway, the wind having gale force over dame
ter of at least $500 miles, Changes of tempera-
ture, like those of pressure, are much more fire.
quent and extensive in winter. The differences
are greatest between lat. 400 and 45o N and long,
400 to 800 W., the most affected by the meet
ing of the Gulf Stream and the Polar current
place of almost constant rain, and the breeding
place of many storm-areas.
MAKING A SEA.
During many years spent in Tunis, Col. Roud-
aire surveyed four great depressions or "shotts,"
extending below sea level in such position that
they may be filled with water by means of a canal.
These depressions-name Tedied, Djerid, Rharsa
and Merir-could thus be changed into lake
more than rs feet deep, and having an area of
g. 164 square miles. The creation of this lake and
the consequent improvement of much surround
ing country formed the favorite project of Col.
ROudaire, and now seems likely to be accomplish
ed in spite of its authors death. The artesian
wells tried in the district, and from which a rev.
enue in aid of the canal was expected, are prov
ing successful. The first well, sunk in 1885 to a
depth of 295 feet, commenced yielding water at
the rate of ,76O gallons per minute, and has now
increased its flow to 1890 gallons per minute
According to Sir F. de Lesseps, the banks of the
river Melah, which fifteen months ago were deserts,
are now populated; and very shortly the canal
will be commenced.
HOW FATIGUE OPERATES.
After study of some years, Prof. Mosso, of
Turin, finds that when fatigue is carried beyond
the moderate stage, at which it is decidedly bene-
fetal, it subjects the blood to decomposing pro-
cess through the inftration into it of substances
which acts as poisons, and which, when injected
into the circulation Of healthy animals, induce
uueasiness Tue signs OF EXCESSIVE eXnaus-
ton. When within the resisting power of the
subject, fatigue has its pleasures and even joys,
these being the expression of the organic con-
sciousness that bodily loss of tissue is being bal
anced by reconstruction Mossos experiments
were performed on Italian soldiers, and they
proved, among the other results, that the stature
and power of the modern warrier are fully equal
to those of the ancient Roman.
MISCELLANEOUS.
By means of mixture of pulverized magnesium,
chloride of potash and sulphide of anthony,
Messrs GoedicKe and Miethe produce explosive,
lightning like illumination which is likely TO be of
much value in photograpy. The flash lasts one
fortieth of second, and provides cheap and
practical method of securing instantaneous pic
lures at night or in dark places.
Weak carboic acid solution, sponged over skin
and hair is said to drive away any and all insects.
From an examination of butter from various
parts of France, M. E. Ducaux learns that con-
trary to general opinion, the quality of this arti-
Gle depends largely on the breed of cattle and
their food, the pasture-soil, influence of season,
age of milk, etc.
In one district of Algeria, $4,000 gallons of
grasshoppers' eggs have been collected and burned
this year.
Paper, or other fbrous form of cellulose, passed
| through bath of nitric acid, and then washed,
becomes celluvert, new material of great tough
| nass